Traditionally, a single company operating in a defined service area has provided local telephone service to all users in that service area. In today's competitive telecommunications environment, however, new carriers have begun providing local telephone service in areas formerly served exclusively by a single carrier. To provide local telephone service, each local carrier, also known as a local service provider (LSP), must obtain a block of 10,000 telephone numbers for each rate area they serve. The reason for this is that the LSP uses the customer's telephone number exclusively to determine where the customer is located for billing purposes.
For example, a new carrier may obtain a block of numbers defined by NPA-NXX-XXXX to provide local telephone service, where NPA represents the area code, NXX represents the central office location code and XXXX represents the unique numbers for specific customers. The combination of NPA-NXX, however, provides 10,000 numbers that can only be used to serve customers living within a defined geographic area known as a rate center. The rate center is used for billing purposes. If the LSP wishes to provide service to customers residing in a different rate center, the LSP must obtain another block of numbers defined by a different NPA-NXX to provide service in the other rate center.
A problem with such a system is that the number resource is being exhausted as the competition for local telephone service increases. A need therefore exists for a method to reduce strain on the current numbering resource caused by the increase in LSPs.